Power lawn mower



Smaentor (tfornegs o y a L.. W

2 SHEETS-SHEET 2 f'fO/Q/ fa/L H V. TIMMINS POWER LAWN MOWER Dec. 30, 1952 Filed Dec. 24. 1949 Patented Dec. 30, 1952 POWER LAWN ll/IOWER Harold V. Timmins, Detroit, Mich., assigner to The Moto-Mower Company, Detroit, Mich., a

corporation of Michigan Application December 24, 1949, Serial No. 134,909

2 Claims.

This invention relates to lawnmowers and, in particular, to power lawnmowers.

One object of this invention is to provide a lawnmower having a chassis which, with but slight modifications in the length of the cutting reel, may be used interchangeably for the manufacture of hand lawnmowers or power lawnmowers.

1 Another object is to provide a lawnmower wherein the chassis is so constructed that the front tie rod serves not only its normal function of strengthening the frame but also as a support for a pulley and drive sprocket by which the lawnmower chassis may be completed as a power lawnmower by adding an engine and a cutting reel having a drive sprocket.

Another object is to provide a lawnmower of the foregoing character which is adapted to employ an engine of any one of several different makes, the driving arrangement being sufficiently flexible to be driven by such engines without requiring alterations in the engines themselves.

Another object is to provide a lawnmower of the foregoing character having a simple and effective engine mounting and height adjustment by which the height of the cutter bar above the ground may be regulated quickly and easily without disturbing the level position of the engine.

' In the manufacture of lawnmowers as hitherto conducted, one of the factors resulting in an increased cost of manufacture has been the necessity of providing a special chassis for the power y lawnmower which differed in construction from that used for hand lawnmowers, so that the power lawnmower manufacturer could not obtain the benefit of the low cost of manufacture resulting from the mass production methods and enormous quantities of units produced in hand lawnmower manufacture. The present invention provides a lawnmower chassis which can be used either for a hand lawnmower or for a power lawnmower without requiring any great modifications.

In the drawings:

Figure 1 is a top plan view of one form of power lawnmower employing the convertible chassis of the present invention, as employable for either a hand lawnmower or a power lawnmower;

Figure 2 is a side elevation of the power lawnmower shown in Figure 1 but having six blades;

Figure 3 is a rear elevation of the lower lawnmower shown in Figures 1 and 2 but having six blades;

Figure 4 is a rear elevation of a modified power lawnmower having six blades and; v

Figure 5 is a vertical line 5--5 in Figure 4.

Referring to the drawings in detail, Figure 1 shows a power lawnmower, generally designated I0, as consisting generally of a convertible chassis II having an attachable driving mechanism I2 by which it may be driven from an internal combustion engine I3. The chassis II is pushed and guided by a handle assembly, generally designated I4.

The chassis I I, which is usable either for a hand lawnmower or a power lawnmower, consists of laterally spaced side frames I5 interconnected by a tie rod I6 at the upper forward end thereof and having rearwardly and downwardly extending arms Il between which a cutter bar I8 is bolted as at I9, the cutter bar carrying a xed cutting blade 20. The cutter bar I8 thus serves not only as a blade support but also as a rearward tie member for the guide frames I5. J ournaled in the in wardly extending bosses 2| of the side frames I5 is a cutting reel shaft 22 (Figures 1 and 3) rotatably supported in bores 23 therein and carrying a cutting reel, generally designated 24, consisting of spaced spiders 25 carrying spiral cutting blades 26 on their outer ends, the spiders 25 hav ing hubs 21 mounted on the cutting reel shaft 22. The fixed cutting blade 20 and cutting reel 24 are positioned adjacent one another so that the cutting edges of the spiral cutting blades 26 move across the cutting edge of the fixed cutting blade 2i! as the cutting reel 24 is rotated.

Mounted on the outer ends of the cutting reel shaft 20 are pinions 28 meshing with internal gears 29 integral with ground wheels 3i). The ground wheels 30 are rotatably mounted upon studs 3I passing through bores 32 and 33 in the ground wheels 29 and side plates I5 respectively and held in position by nuts 34 threaded on the inner ends of the studs 3I. The side frame arms I'I at their rearward ends are provided with rows of vertically spaced bolt holes 35. A bolt 36 passes through one of each set of bolt .holes and through a ground roller supporting arm 3l. The ground roller supporting arms 31 at their lower ends are provided with bosses 38 bored as at 39 to receive the opposite ends of a ground roller shaft 40 carrying a ground roller 4I. The upper ends of the ground roller supporting arms 31 are secured, as by welding, to a cross rod 42 which in turn is secured by J-bolts 43 to the rearward end of an engine platform 44. The J-bolts 43 pass through a cover plate 45 of sheet metal interposed between the cross rod 42 andthe platform 44. The forsection taken along the 3 ward end of the engine platform 44 is secured by J-bolts 46 to the tie rod I6, the J-bolts 4E also passing through the cover plate (Figure 1).

Extending inwardly from the side frames I5 are pivot pins or studs 4'! mounted in bosses 48 and carrying the suitably bored lower ends of side bars 49 ofthe handle unit I4. The side bars, 49

are bentI inward to converge toward one another although having parallel inner and outer end portions (Figure l) and at their outer ends are interconnected by a handle rod 59 upon whichis mounted a handle 5I of wood or other suitable material. The handle rod 53' isf preferablyupsetl at its opposite ends to retain it in position. A bracket 52 is riveted or otherwise secured to one of the handle unit side bars 453v andy carries a pivot bolt or stud 53 upon which is mounted the clutch lever 54 by which the driving connection between the engine i3 and the cutting reel 24 is made: or: broken, as. desired. For this purp`ose,.a control rod 56 is pivotally conne'cte'das,` at` 5'Iv to the. clutch control lever 54 and extends-z downward tof a pivotal connection 5.3.' with the lower endgcf aclutch lever 59;. the midporti'on ofwhichv isv pivotally mounted on the tie rod IG and the upper. portion of which carries, a stud. upon. which. a Contact pulley 5i isrotatably mounted'.

-The engine -isf bcltedlaslat: 6.2 tothe engine platform 44 and is of any suitable conventional. type: The details* of the. enginey I3' are. beyond the scopefof thev present. invention except.' that it isI providedwith the,v usual crankshaft or output,`

Mounted on theouter end: of. the shaft Si ista 1 drive. pulleyV 68' around whichv passes: an. endless belt 69, preferably a. V`belt'.. TheA belt*I 69. also passes over' the periphery of the pulley 6|' and around a driven pulley.` l having an elongated hun. 1 I: bored. as at: 12.' to rotateV` loosely upon. the tief rod` I5". 'fluev hub 'H' also. carries. ai sprocket..

'I3A and projects beyond it (Figure. L) to engagev a.. boss T4 extending inward fromV the adjacent*- side; frame I5.. A. retaining colla-r 'f5 is'` pinned" or'dth'erwisev suitablysecured to the tie rodi. I'G'oni ther-opposite. side of the clutch-1 lever 59 from the pulley 'ill and holds-f these parts in assembly. An:

endless sprocket chain I5 meshes with the sprocket I3 and transmits the drive from it toa` sprocket TI` mounted on the cutting'reel-shaft'ZZ. Arrear 18; extendsI rearwardly from` the upper: arm of the' clutch lever 59? andl carriesthe for-l wardv end of ai tension' spring. T3", the rearward endl of which is anchored to an ear 85 which is secured to and: extends upward fromthe cover plate 45.

The lawnmower, generally designatde B5, shown. inV Figures 4y and 5V is generally similar in most respects to the lawnmower IE!Y of" Figures I tord The: piinon. (S4V inclusive. and similar partsA are designated withV they same numerals. In Eigure 4; however.'` the; roller supportingarms 37 terminate shortlyfabovethe extension arms I l of the sidey framesV I5.V Moreover, the single ground roller 4I cfFigure 21 is replaced byv a pair of axially spaced ground'l rollers 85. Connected as by a` J-bolt 81.Y tothe roller shaft do in the space between. the ground rollers 86 is the lower end of, the` uprightV 88 of'.

a T-member 89, the cross member of which is secured by the J-bolts 43 to the engine platform 44 and cover plate 45. The cross member 90 is of circular cross-section (Figure 5) so as to pivot momentarily in the J-bolts 43 when the latter are loosened. The T-mcmber 89 furnishes a simplied yet strong connection between theengine Aclatform 4.4 andthe ground roller shaft-40.

Operation In the assembly of the mower I as a hand mower,. thel engine platform 44, cover plate 45 and engine I3 are, of course, omitted, together with the driving; mechanism I2, and the tie rod I6 is thus' completely unencumbered. The clutch control lever'll and bracket 52 are also omitted from the handle side.` bar 49, and the sprocket 'I1 is likewise omitted from the ground reel shaft 22. The` pinions 28, which in both the hand and power lawnmowers are of the conventional unidirectional type', are reversed-- in the handV lawnmower so that the ground wheels 30 drive theV cutting reel shaft 22, whereas-in the power lawnmower, the cutting reel shaft drives the ground wheels: 36. Moreover; in large scale production ofthe hand lawnmower, al longer'cuttingv reel 24 would customarily beused?, since thespace at'itsv left-hand end is no longer needed for the sprocket'Y 'ilA and sprocket chain T6. Thus, with practically no modilcations', the chassis I'I: of Figure I can bev used either forl a hand lawnmower or for a power lawnmower. Y

In operation', the hand lawnmower. is used in the same manner as anyhand lawnmower.

ing the clutch control lever'54 to swingV the clutch leverv 59 and the pulley G'I' intocontact' with the V-belt 69 so as to take up the slack in thisbelt. When the slack isl taken up in` this manner, power is,l transmitted tothe pulley 10, rotating` the hub@ Til? and sprocket T3, this rotationbeingA transmitted? by the sprocket chain 'iti to.: the

sprocket Ll onthe reelshaft-ZZ'.. Theconsequent.

rotation. of: theft reel shaft. 22l transmitspower'. through the: pinionsf 28 to the' internal' gears iti)4 on. the ground wheel's 3i), causing them` to' rotateV and. propel the mower; while the operator. guides;

it by" gras-ping' th'e'- handle` 5I and: swinging: iii-to andv fro to steer. it..k Tof halt` the:A mower'at any time;. thev operator` merely'L grasps' the. clutch con-- trol; levery 54 and; swings itskk upperv armV towardi thereby' swinging the.` pulley 6I: awayfrom the` belt. 69 the slackness; which immediately de velopsg. in: this belt instantly interrupts the, drive toy theA pulley,Y lll.. and` the.' lawnmower halts.,

Inyeither` the power Vlawnmower orthe hand mower,y` the position; ofthe' cuttingbladel` 2Q relaf` ti-velyf to the ground` can quickly andeasily be4 adjusted; merely by removing the bolts 3S and replacing.y them.` mother. 4holes 3.5.' inthe, side frame extensionarms IJ.. This change. of. height ,inA the cutting blade 2U" does not affect the level ofthe engine platform 44 or engine ItV to any appreciable extent; asthearms'l' (FigurerZ or' the uprightv 88 ofthe T-member 8`9= swing through.y aL negligibleangleinj making thisy adjustment. Y

L. In combination withv atlawnmower having a pair. of:y transversely-spaced side.; frames. withv upper: edges sloping; downwardly fromffront to; rear thereofj and: having a transverseA front tie rodinterconnecting the forward portions of said side frames and a rotaryV cutting reel journa'led-atrits opposite ends in-saidfside.frames, anienginelmv-l TheV lower? lawnmowerA madeA onV the same chassis is operated by starting the motor I3 and then Vshift-A ing a base with its forward portion supported by said tie rod and having a, drive wheL'a ldriven wheel rotatably mounted on said tie rod and drivingly connected to said driving wheel, a drive sprocket rotatably mounted on said tie rod and fdrivingly connected to said driven wheel, Ia driven lsprocket drivingly connected to said cutting reel, 'and a sprocket chain drivingly interconnecting said sprockets. i

I2. In combination with a lawnmower having a -pair of transversely-spaced side frames with -upper edges sloping downwardly from front to rear thereof and having a transverse front tie rod interconnecting the forward portions of said side frames and rotary cutting reel journaled at its opposite ends in said side frames, an engine having a base with its forward portion supported by said tie rod and having a drivewheel, a, driven wheel rotatably mounted on said tie rod and drivingly connected to said driving wheel, a drive sprocket rotatably mounted on said tie rod and drivingly connected to said driven wheel. a driven sprocket drivingly connected to said cutting reel. a sprocket chain drivingly interconnecting said sprockets, an endless flexible member drivingly interconnecting said Wheels, a clutch Iarm swingably mounted on said tie rod, an idler wheel rotatably mounted on said arm and swingable into engagement with said endless iiexible member, and mechanism for urging said idler wheel into engagement with said endless flexible member.

HAROLD V. TIMMINS.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,088,293 Funk July 27, 1937 20 2,250,418 Funk July 22, 1941 2,468,839 Rodesci May 3, 1949 2,519,039 George et al Aug. 15, 1950 

